Office of Compensation Analysis and 

Support 

Technical Information Bulletin 

Document Number: 

 OCAS-TIB-0010 

Effective Date: 05/18/2005 

Revision No. 1 

Special External Dose Reconstruction Considerations for 

Glovebox Workers 

Page 1 of 12 

Signature on File 

Approval: Date: 5/18/05

 J.W. Neton, Health Science Administrator 

Supersedes: 

Revision 0 

RECORD OF ISSUE/REVISIONS
 

ISSUE 

AUTHORIZATION 

DATE 

EFFECTIVE 

DATE 

REV. 

NO.

 DESCRIPTION 

5/18/2005 5/18/2005 1 Updated document to provide methodology and 

guidance on applying correction factors to glove 

box workers for over and under estimation of 

dose. 

1.0 Purpose 

The purpose of this technical information bulletin (TIB) is to provide guidance on dose reconstructions 

for glove box workers. It can be used in overestimating or underestimating dose in accordance with 

the dose reconstruction flow process detailed in OCAS-PR-003, “Performing and Reporting Dose 

Reconstructions”. Specifically, if the initial overestimate dose results in an excess of 50% of the POC 

this TIB will then be used for an underestimate in the secondary dose evaluation using low end values 

for dose correction factors. Guidance on “best estimate” dose reconstruction will be published in a 

separate document. This TIB discusses the special exposure characteristics that may be encountered 

by energy employees who work with gloveboxes and provides special dose correction factors or 

modifiers that should be applied to affected energy employee’s dose. It should be noted that 

throughout this technical information bulletin, the term glove box is used, however, in the early years 

of the Atomic Energy Commission (AEC) facilities; these types of units were commonly called dry 

boxes as their original intent was to isolate radioactive materials. Throughout this report these terms 

should be considered equivalent. 

A general approach will be considered for a single glove box and a sequence of connected glove 

boxes. In both these cases, geometry and energy are the predominant variables. 
 

Effective Date: 5/18/2004 Revision No. 1 Procedure No. Page 2 of 11 

OCAS-TIB-0010 

A general approach will be considered for a single glove box and a sequence of connected glove 

boxes. In both these cases, geometry and energy are the predominant variables. 

2.0 Special Exposure Considerations 

There are two special considerations when conducting dose reconstructions for glovebox workers. 

The first is the exposure geometry and the second is photon energy considerations. The combination 

of these factors could result in an underestimation of the reconstructed dosimeter and missed dose to 

organs located in the lower torso region of the body (stomach, liver, bladder, prostate, ovaries, testes, 

etc...) The degree of underestimation is dependent on many factors, which include the distance 

between the radiological source (exposure geometry), the materials used to construct the glove box 

(attenuation or shielding), and the relative duration (time) that an energy employee conducted work in 

the glovebox. In general, very little is known about the duration of the exposure which is typically 

dependent upon the specific duties of the energy employee. 

2.1 Exposure Geometry 

Exposure geometry is a special consideration in dose reconstruction of energy employees who 

primarily worked in glove boxes. An underestimation of the dose could occur if the energy employee 

wore his/her dosimeter on the lapel and not the center area of the chest or on the waist. This 

underestimation could result due to the difference in relative distance between the external radiation 

source, the organ of interest, and the dosimeter. Only organs in the lower torso are affected, since 

due to glove box design these could be closer to the radiological source than the dosimeter. The 

dose to lung is considered to have been reasonably approximated by the dosimeter at least to within 

the dosimeter uncertainty and the dose to the face and head would have been slightly lower than the 

dose measured by the dosimeter worn on the lapel. 

2.2 Photon Energy 

Another special consideration is the photon energy spectrum measured by the dosimeter. Low 

energy photons have a relatively low penetration power and are easily attenuated by thin metal 

shielding. As a result, the design of the glovebox is an important consideration in accurately 

estimating the low energy photon dose. A review of the literature indicates that the design of 

gloveboxes varied widely.1, 2 In some instances almost fully metal glove boxes were used with only a 

small area for viewing (Figure 1), other glove boxes had relatively large viewing areas (Figure 2-4), 

and others had a combination of multiple viewing areas with some opening center mass of the lower 

torso (Figure 5). 
 

 

 

Effective Date: 5/18/2004 Revision No. 1 Procedure No. Page 3 of 11 

OCAS-TIB-0010 

 Figure 1 Plutonium gloveboxes at LANL (1) Figure 2 Plutonium gloveboxes at Chalk River (1)

 Figure 3 Plutonium gloveboxes at Hanford (2) 
 

 

 

 

 

Effective Date: 5/18/2004 Revision No. 1 Procedure No. Page 4 of 11 

OCAS-TIB-0010 

Figure 4 Plutonium gloveboxes at LANL’s CMR facility (1)

 Figure 5 Other plutonium gloveboxes at 

Hanford. Note the viewing area in direct line 

with the lower torso in the center between the 

gloves. (2) 

Since the actual glovebox design is not known for each dose reconstruction scenario, a claimant 

favorable approach is used by assuming the glovebox had a large viewing face with relatively little 

difference in photon attenuation between the external source and the organ of interest and between 

the external source and the dosimeter. This is considered a reasonable but necessary claimant 

favorable assumption, since identifying the actual glovebox design at each facility (DOE site, building, 

room, etc.) would be time consuming. In addition, during the course of an energy employee’s 

employment, it is likely that they conducted work in many different types of gloveboxes, thus a time 

dependent work location correction factor for each glovebox design would be necessary to account 

for such differences. The tendency of this assumption is toward an overestimate of the dose rather 

than an underestimate. 

While the face (viewing area) of a glovebox was typically constructed using a clear polymer type 

material such as Lucite3

, the sides and bases of gloveboxes are almost always constructed of sturdy 

materials such as wood, aluminum, and most commonly steel. These materials generally shield an 
 

 

Effective Date: 5/18/2004 Revision No. 1 Procedure No. Page 5 of 11 

OCAS-TIB-0010 

individual worker from side exposure to low energy photons. As a result the low energy photon dose 

is virtually 100% from the anterior- posterior exposure geometry duets the radiological materials in the 

specific glovebox where the energy employee conducted his/her work. On the other hand, the 

intermediate and high energy photon dose would be a combination of the direct work in the glovebox 

as well as surrounding gloveboxes and process lines. Due to these differences, two different 

exposure correction distributions were developed; one for low energy photons (< 30 keV), and one for 

intermediate (30-250 keV) and high (> 250 keV) energy photons. 

3.0 Methodology 

3.1 Low energy photons from a single glovebox 

An evaluation of the degree of dose underestimation by the dosimeter was conducted using several 

different exposure geometry scenarios. In each scenario the radiation source was assumed to be 

directly in line with the specific organ of interest in the lower portion of the torso. To accurately 

estimate the dose underestimation, the actual height of the glovebox with relation to the energy 

employee’s organ of interest and the distance to their lapel would be necessary (Figure 6). Using 24 

inches is a reasonable but necessary claimant favorable assumption for simplicity of calculation. In 

general, the correction factors for smaller stature workers would be less than those indicated in this 

technical information bulletin as the 24 inches is based on a moderately tall worker. In some 

instances especially in the case of small stature workers, some of the organs could be below the 

bottom of the glovebox, thus low energy photons are virtually completely shielded (attenuated) and 

intermediate energy photons more attenuated than those measured on the dosimeter (Note the 

relative difference in worker stature in Figure 3). 

≈ 24 inches (61 cm) 

≈ 12 inches (30 cm) 

 Figure 6 Diagram of Human Torso (4) 

An average distance of 24 inches (61 cm) was assumed to be the distance between the lower torso 

and the lapel. The distance between the radiation source and the lower torso was varied from 6 
 

 

Effective Date: 5/18/2004 Revision No. 1 Procedure No. Page 6 of 11 

OCAS-TIB-0010 

inches to 18 inches. These distances were selected as the general range from which a worker could 

conduct most of their work in the glovebox. A source closer than 6 inches while technically possible 

in some glovebox designs is not very likely given the body geometry and with respect to the glovebox. 

In some instance (Figure 2) a nearly straight down movement would be needed position a source 6 

inches from the lower torso. On the converse, 18 inches was selected as a reasonable upper 

distance. While some workers with longer arms might have been able to reach the back of the 

glovebox, in general a comfortable working distance for most workers would be between 10-14 inches 

between the source and the lower torso with a central tendency estimated at approximately 12 

inches. 

Using the inverse-square distance variation discussed above, the underestimation of the dose as 

measured by the dosimeter would range from a factor of 17.0 at 6 inches to 2.8 at 18 inches. Since 

this correction factor distribution is somewhat subjective and based on reasonable assumptions, a 

triangular distribution is assumed to reasonably approximate the uncertainty distribution (Figure 7). 

The minimum parameter of this triangular distribution is 2.8, the mode is 5.0, and the maximum is 

17.0. 

Frequency Chart

 mR/mR 

.000 

.010 

.019 

.029 

.039 

0 

600.7 

2403 

0.0 5.0 10.0 15.0 20.0 

62,000 Trials 62,000 Displayed 

Forecast: Low Energy Correction Factor 

Figure 7 Triangular distribution assumptions for the low energy photon correction factor 

3.2 Intermediate and high energy photons from multiple gloveboxes 

The correction factor provided in Figure 7 is a reasonable estimate for low energy photons in a single 

glove box; however, to use this factor for intermediate and/or high energy photons could significantly 

overestimate the true organ dose. This overestimation would result since radiation sources at 

distance greater than 30 inches were not considered although clearly they would have been 

measured by a dosimeter located on the lapel. 

At source distances greater than 48 inches, the relative difference between the dose to the lower 

torso and the lapel is less than 25% (factor 1.25) which is typically within the uncertainty of the 

dosimeter measurement. Thus the intermediate and high energy photon dose to the lower torso is 

approximately equal to the dose measured by the dosimeter on the lapel. 
 

 

 

Effective Date: 5/18/2004 Revision No. 1 Procedure No. Page 7 of 11 

OCAS-TIB-0010 

To estimate the contribution from multiple gloveboxes, a long line source at the three distances 

discussed in section 3.1 (6, 12, and 18 inches) was used. Microshield®5

 calculations were performed 

using these scenarios assuming 5 - 48 inch gloveboxes in a row. Using this methodology, the dose 

contribution from uniform sources lined in a glovebox varied from 57% to 76%. The central estimate 

assuming the 12 inch distance was 64%. This is considered a reasonable and possibly an upper 

bound of the dose contribution from intermediate and high energy photons, especially since this 

contribution neglects doses that could be received from dual glovebox lines as shown in Figure 1. 

However, giving some credit to the possibility that 100% of the intermediate and high energy photon 

dose could be from the single glovebox, where no dose fraction modification would be appropriate, a 

new relative fraction distribution can be developed assuming a triangular distribution with a lower 

bound of 0.357, a mode of 0.64 and an upper bound of 1.0. This distribution was combined with the 

correction factor distribution through Monte Carlo sampling using Crystal Ball®5

 to estimate the 

correction factor that should be applied to the intermediate and/or high energy measured photon dose 

(Figure 8). 

Frequency Chart

 mR/mR 

.000 

.013 

.025 

.038 

.051 

0 

789.2 

3157 

0.00 5.00 10.00 15.00 20.00 

62,000 Trials 62,000 Displayed 

Forecast: PI/PH Correction Factor 

Figure 8 Intermediate and high energy photon correction factor distribution 

This joint distribution is best approximated as a log normal distribution with a geometric mean of 5.0 

with a geometric standard deviation of 1.55. The upper 95th% of the distribution is 10.3. 

3.3 Reasonable Claimant Favorable Assumptions 

Listed below are several claimant favorable assumptions used in the development of this 

methodology that could result in an overestimate of the actual dose. 

• Claimant favorable glovebox design 

• Direct line of sight to organ of interest 

• Distance from lower torso to lapel based on tall workers 
 

Effective Date: 5/18/2004 Revision No. 1 Procedure No. 

OCAS-TIB-0010 

Page 8 of 11 

Obtaining data to precisely evaluate each of these parameters requires extensive time and research 

on an individual basis and in some instances it is known that the information cannot be obtained (i.e. 

facility has undergone D&D or other significant modification over time). 

4.0 Applicability to Neutron Doses 

The high energy photon correction factors described above may also be appropriate to measured 

neutron dose and potentially to some applications using neutron to photon (n-p) ratios. An evaluation 

of the applicability to neutron dose requires a site specific evaluation. 

When a neutron to photon ratio method is used to estimate the neutron dose, it is important to know 

the general location of the photon and the neutron dosimeter. In the case of the Savannah River 

neutron to photon (n-p) ratios, the ratio was developed from joint measurement data of the TLD 

typically worn on the lapel and the neutron dosimeter (belly button dosimeter) worn around the waist. 

In this instance, the correction factor should not be applied since the measured neutron dose is a 

good representation of the dose to the lower torso. In later years, however, when the dosimeter 

combined photon and neutron TLD elements, a correction factor would need to be applied. 

However at other facilities, if the NTA film dosimeter was worn on the lapel and a ratio was 

determined based on a photon dosimeter also worn on the lapel. Then the correction factor should be 

applied. The most efficient method for doing so would be to apply the correction factor to the photon 

dose before applying the neutron to photon ratio. 

5.0 Special Dose Conversion Factor for Plutonium 

In NIOSH’s External Dose Reconstruction Implementation Guideline7, organ dose conversion factors 

are tabulated by averaging the energy specific values from ICRP 74 (1996)8

 over the IREP photon 

energy range. The lowest photon energy interval in Interactive RadioEpidemiological Program (IREP) 

is categorized as less than 30 keV. Plutonium emits several x-rays in this energy range; however, a 

simple average as used in the Implementation Guideline may not result in the most accurate dose 

conversion factor. For Plutonium work, the average x-ray energy is approximately 17 keV. As a 

result, using 20 keV as a claimant favorable single point estimate is most appropriate. Since the low 

energy photon dose from glove box work is predominately in the anterior-posterior (AP) geometry, 

single point estimate values were calculated for 16 organs listed in ICRP 748 . When estimating the 

low energy photon organ dose from glovebox work, the values in Table 1 should be used. 
 

Effective Date: 5/18/2004 Revision No. 1 Procedure No. 

OCAS-TIB-0010 

Page 9 of 11 

Table 1 Special Dose Conversion Factors (DCF's) for Plutonium glovebox work. DCF’s 

These were calculated assuming AP geometry and 20 keV mono-energetic photons. 

Organ 

Personal Dose 

Equivalent (Hp(10)) 

– Organ Dose (HT) 

Ambient Dose 

Equivalent (H*(10)) 

– Organ Dose (HT) 

Exposure (R) – 

Organ Dose (HT) 

Bladder 0.146 0.147 0.088 

Bone (Red Marrow) 0.024 0.024 0.014 

Bone (Surfaces) 0.165 0.166 0.099 

Breast (Female) 0.761 0.762 0.457 

Colon 0.024 0.024 0.015 

Esophagus * * * 

Eye 1.493 1.495 0.897 

Ovaries * * * 

Testes 0.823 0.825 0.495 

Liver 0.068 0.069 0.041 

Lung 0.050 0.050 0.030 

Remainder 0.053 0.053 0.032 

Stomach 0.144 0.144 0.087 

Thymus 0.264 0.264 0.158 

Thyroid 0.586 0.587 0.352 

Uterus 0.002 0.002 0.001 

* 20 keV values not listed in ICRP 748 – Use < 30 keV DCF’s from OCAS-IG-0017or an appropriate surrogate organ 

6.0 Summary 

This Technical Information Bulletin provides guidance for dose reconstruction to organs located in the 

lower torso. The correction factors for over and underestimation of dose provided in Tables 2.a and 

2.b respectively are for photons emanating from gloveboxes and measured using a dosimeter worn 

on the lapel. The < 30 keV factors should be applied to the 17 keV dose typically measured with the 

open window of the dosimeter. The dose correction factors from Table 1 are then applied for 

plutonium exposures. The 30-250 keV factors should be applied to all intermediate and high energy 

photon doses recorded either as the shielded element of the dosimeter or as the deep dose. 

Table 2.a Lower torso overestimate dose and/or exposure rate correction factors for glovebox work 

Photon Energy Distribution Minimum Mode Maximum 
 

 

 

Effective Date: 5/18/2004 Revision No. 1 Procedure No. Page 10 of 11 

OCAS-TIB-0010 

< 30 keV Triangular 2.8 5.0 17.0 

Geometric Mean Geometric Standard Deviation (GSD) Upper 95th% 

30-250 keV 

> 250 keV Lognormal 5.0 1.55 10.3 

Table 2.b Lower torso underestimate dose and/or exposure rate correction factors for glovebox work 

Photon Energy Distribution Minimum 

< 30 keV Triangular 2.8 

Minimum 

30-250 keV 

> 250 keV Lognormal 2.0 

7.0 References 

1. A. S. Coffinberry and W. N. Miner, The Metal Plutonium, The University of Chicago Press, 

Chicago, Illinois, 1961. 
 

 

5 

Effective Date: 5/18/2004 Revision No. 1 Procedure No. Page 11 of 11 

OCAS-TIB-0010 

2. Office of Environmental Management, (1997) U.S. Department of Energy. Linking Legacies: 

Connecting the Cold War Nuclear Weapons Production Processes to Their Environmental 

Consequences, DOE/EM-0319, U.S. Department of Energy, Washington D.C. 

3.	 Watson, E. C. (1959) A Film Technique for Measuring the Exposure Dose from Plutonium, 

Health Physics, Vol. 2 pp. 207. 

4. Merck (2004), The Merck Manual – Second Home edition, illustration obtained at the 

following website. http://www.merck.com/mrkshared/mmanual_home2/fg/fg001_1.jsp 

Grove Engineering (2002), Microshield Program version 5 User Manual, Rockville Maryland. 

6. Decisioneering Inc. (2000), Crystal Ball 2000 User Manual, Denver Colorado. 

7. 42 CFR 82, Methods for Radiation Dose Reconstruction Under the Energy Employee 

Occupational Illness Compensation Program Act of 2000; Final Rule, Federal Register/Vol.67, 

No. 85/Thursday, May 2, 2002, p 22314. 

8. NIOSH, (2002) External Dose Reconstruction Implementation Guideline, Rev 1, OCAS-IG001, National Institute for Occupational Safety and Health, Office of Compensation Analysis 

and Support, Cincinnati, Ohio.